Questions about SARS-COV-2 and gastrointestinal COVID-19

A patient who was admitted for treatment of rectal adenocarcinoma had specimens taken from the rectum during the performance of an ileostomy (the cancer was cut out and his bowel was given a new outlet to the skin.) Three days later he developed symptoms and was diagnosed with COVID-19 that progressed to pneumonia. The samples taken at surgery showed replicating (growing) SARS-COV-2 virions (individual virus particles) in the tissue under the electron microscope (EM.)

The only conclusion you could make from that is that he was shedding virus in his stool three days before he developed symptoms of COVID-19.

This is a typical phenomenon. A case series of 42 patients with confirmed COVID-19 had the virus isolated from the stool of 28 of them, which persisted for an average of a week after it was no longer detectable in the nose.

A large meta-analysis early in the outbreak found 48% of 4243 patients with positive tests for virus RNA in stools, but only 18% had symptoms. Again, virus RNA was detected in stool after it had disappeared from respiratory samples.

Another study, with 95 patients, found that if anorexia and nausea are included as gastrointestinal (GI) symptoms, 58 of the patients (more than half) did in fact have GI problems. 31 of 65 patients whose stool was tested were positive for virus RNA.

This study, which included 116 consecutive patients, identified liver enzyme increases in 40% of the 65 patients tested for liver function. There were 32% of all patients who complained of GI symptoms, but they were mild compared to the cough and dyspnea. The authors also remarked that GI symptoms were never the first sign of illness.

These studies make it clear that SARS-COV-2 frequently, if not always, infects the GI tract, but doesn’t always cause diarrhea. These symptoms are relatively mild– unlike those in the blood vessels, lungs, and heart. The virus even affects skin: this report from the United Kingdom says that 8-9% of patients complained of rashes.

The virus invades the lung and causes pneumonia in a large proportion of patients with symptoms. It also affects the heart in most patients, if the studies of post-viral heart MRI scans are accepted. It seems to be the case that the virus can invade every part of the body because it affects blood vessel endothelium (lining) and there is no organ other than the cornea free of blood vessels.